Genome-Wide Identification Analysis of the Auxin Response Factors Family in Nicotiana tabacum and the function of NtARF10 in Leaf Size Regulation

Auxin is well recognized for its involvement in several developmental processes like floral and leaf development and shoot elongation. The transcriptional regulation of auxin-responsive genes is mediated via auxin response factors (ARF). In this study, we identified 46 ARF genes in Nicotiana tabacum , performed phylogenetic analysis and investigated their structure, conserved domains, and motifs. Our results demonstrate that some of NtARF genes are regulated by mi-RNAs and expression in multiple tobacco tissues. Additionally, the leaf NtARFs display a diverse expression pattern in vein and shoot apical meristem in response to exogenous auxin stimulus. Transgenic NtARF10 -overexpressing Arabidopsis plants exhibit larger leave areas, cell area, and more numerous cell numbers compared to wild-type plants and include several upregulated genes involved in cell division and expansion, including AtCYCD3 , AtTCP1 , AtTCP20 , AtXTH33 , and AtARGOS . This suggests NtARF10 might play a role in the regulation of leaf size. Our study contributes to a better understanding of the characteristics of the ARF family in tobacco and provides a basis for further functional research into NtARFs .